Assembly suitable for life testing a multi-dimensional force transducer

Abstract

A test assembly suitable for life testing a computer pointing stick includes a rigid shaft that is rotated by a motor and a mounting mechanism for holding and positioning the pointing stick under test in a coaxial relationship with the rigid shaft. A cantilever spring arm is rigidly connected at one end to the rigid shaft so that it rotates with the rigid shaft and is mechanically coupled under lateral spring tension at its other end to the pointing stick. The spring rotates with the rigid shaft and applies lateral force to the pointing stick via a collar attached to the pointing stick, the direction of the applied force rotating with the rigid shaft and cantilever spring. A counter records the cumulative number of flexure cycles required to make the pointing stick functionally fail.

What is claimed: 
     
       1. A test assembly for mechanically cycling a multi-dimensional force transducer through all directions of lateral deflection of a sensing member until the force transducer functionally fails, comprising: 1) a rigid shaft;   2) a mounting mechanism for holding and positioning a force transducer under test, said force transducer having such sensing member defining an axis with respect to which lateral forces applied to said sensing member are sensed, said mounting mechanism positioning said sensing member and said rigid shaft coaxially along a common axis;   3) a motor for rotating said rigid shaft;   4) a cantilever spring having first and second ends, said first end being rigidly connected to the rigid shaft and said second end being mechanically coupled to the sensing member under lateral spring tension so that the cantilever spring can rotate with the rigid shaft while applying a lateral force to the sensing member, the applied lateral force rotating in direction with the rigid shaft; and   5) a counter for recording a cumulative number of rotations of the rigid shaft until the force transducer functionally fails.   
     
     
       2. An assembly according to claim 1, wherein the cantilever spring is rigidly connected at said first end to the rigid shaft at a controllable angle for applying a controlled amount of lateral spring tension force to the sensing member. 
     
     
       3. A test assembly according to claim 1, wherein 1) a collar is attached to the sensing member; and   2) the spring contacts the collar as a bearing on an inside surface of the collar, so that the spring exerts a force on the collar in a direction away from said common axis.   
     
     
       4. A test assembly according to claim 1, wherein 1) a collar is attached to the sensing member; and   2) the spring externally contacts the collar, so as to apply a force to the collar towards said common axis.   
     
     
       5. An assembly according to claim 1, wherein the rigid shaft is rotated by the motor at a speed of from 10 to 100 cycles per second.